How can i clean a micro fiber couch?

i have a couch light beige color...or well it used to be. after having it for 2 years its gotten kinda dingy. id really want it to be as it was before but having 3 kids and all the spills and crayon marks, i have no clue how to clean it. i tried water but it just leaves a ring on the sofa....any advice plz help.